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Dec 05, 2012, 09:00 PM
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cb100's Avatar
Discussion

DX7S tx battery voltage reading is not accurate!!!


Does anyone know if we cud calibrate DX7s tx battery reading? Mine was off by 0.2V. A full 2s pack should be read at 8.4V, yet the tx read it as 8.2V. When my DX7s went off at 7.4V (preset low voltage alarm), i took it out and measured the voltage with a DVM, it read 7.6V(?). Thanks,
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Dec 05, 2012, 09:02 PM
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freechip's Avatar
HH has an acceptable tolerance and it's within the tolerance, you can adjust the alarm accordingly or send it back to HH for calibration.
Dec 05, 2012, 09:05 PM
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cb100's Avatar
That's a huge tolerable error margin by any standard. for these kind of application, it should be within +/- 0.01V. I guess Spektrum's standard is low.
Dec 05, 2012, 09:21 PM
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freechip's Avatar
Call HH and have it serviced or adjust the alarm .2v lower then what you want the battery to actualy be.
Dec 06, 2012, 12:34 AM
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cb100's Avatar
So much for quality control over at spektrum eh... Lol
Dec 06, 2012, 08:05 AM
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richard hanson's Avatar
For heaven's sake!
Dec 06, 2012, 09:55 AM
Surface, Air & Water Rc Toys..
freechip's Avatar
Quote:
Originally Posted by cb100
So much for quality control over at spektrum eh... Lol
You would enjoy the DX5e with 4 basic LED showing the voltage. No more numbers.

PS: Have you check you car's speedo, quality control might also be at play there.
Dec 06, 2012, 11:09 AM
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richard hanson's Avatar
better yet , check household "120v" voltage .
Dec 06, 2012, 11:57 AM
Registered User
Your measuring the battery voltage at no load, while the DX7s can only display the battery voltage while under load (turned on). What your seeing is likely normal.

Can you measure the battery voltage while it is connected to the transmitter and turned on?
Dec 06, 2012, 01:46 PM
B12
B12
Registered User
Quote:
Originally Posted by richard hanson
better yet , check household "120v" voltage .
Mine is 233V. Checked today.
Dec 06, 2012, 06:21 PM
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richard hanson's Avatar
Must be getting power from some old hand cranked Soviet plant -

better make sure the AC is travelling the correct direction..
I think 230 is correct - just like in a Chinese dentist's office.
Dec 06, 2012, 08:36 PM
Just call me Ῥέᾱ
Rhea's Avatar
Quote:
Originally Posted by cb100
Does anyone know if we cud calibrate DX7s tx battery reading? Mine was off by 0.2V. A full 2s pack should be read at 8.4V, yet the tx read it as 8.2V. When my DX7s went off at 7.4V (preset low voltage alarm), i took it out and measured the voltage with a DVM, it read 7.6V(?). Thanks,
Key words here are “took it out”. Measure it the way it is done in the system; under load. No load is always going to be higher.

David
Dec 07, 2012, 02:03 AM
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cb100's Avatar
Quote:
Originally Posted by Rhea
Key words here are “took it out”. Measure it the way it is done in the system; under load. No load is always going to be higher.

David
not when it comes to tx power. provided your theory has some validity to it, how do you explain higher end tx such as jr/futaba or airtronics. even the lower end one like flysky/turnigy 9x, walkera do not exhibit these discrepancies. Placating issues such as this one only make Spektrum/HH perpetuate their inferiority. By being critical about Spektrum's negligence and push them to make it better will help them/us providing better/improved products (WIN/WIN) lol.
Dec 07, 2012, 04:58 AM
Registered User
Quote:
Originally Posted by cb100
not when it comes to tx power. provided your theory has some validity to it, how do you explain higher end tx such as jr/futaba or airtronics. even the lower end one like flysky/turnigy 9x, walkera do not exhibit these discrepancies. Placating issues such as this one only make Spektrum/HH perpetuate their inferiority. By being critical about Spektrum's negligence and push them to make it better will help them/us providing better/improved products (WIN/WIN) lol.
So what you are saying is you didnt test the voltage with a multimeter under load.
Dec 07, 2012, 11:56 AM
Just call me Ῥέᾱ
Rhea's Avatar
I’ll try to keep this short. I spent my working career in the electronic manufacturing and testing industry. Manufacturers of all electronic products set the specifications for proper operation of that product. The only time I have seen questions of inferiority arise is when the user makes up their own understanding of the specs.

David
Last edited by Rhea; Dec 07, 2012 at 04:33 PM.


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